The present invention relates to novel underarm formulations which contain volatile and/or non-volatile alkylmethylsiloxanes of the structure (Me.sub.2 SiO).sub.a (MeRSiO).sub.b or R'Me.sub.2 SiO(Me.sub.2 SiO).sub.y (MeRSiO).sub.z SiMe.sub.2 R". wherein a is 0-5, b is 1-6, a+b is 3-6. y is 0-100, z is 0-100, and R, R' and R" are independently alkyls of 1-60 carbon atoms, with the proviso that at least one of R, R' or R" is an alkyl of 4-60 carbon atoms. The present invention also relates to novel underarm formulations which contain non-volatile aralkylmethylsiloxanes of the structure (Me.sub.2 SiO).sub.a (MeRSiO).sub.b or R'Me.sub.2 SiO(Me.sub.2 SiO).sub.y (MeRSiO).sub.z SiMe.sub.2 R", wherein a is 0-5, b is 1-6, a+b is 3-6, y is 0-100, z is 0-100, y+z.gtoreq.1, and R, R' and R" are independently alkyls of 1-60 carbon atoms or aralkyls of 7-60 carbon atoms, with the proviso that at least one of R, R' or R" is an aralkyl of 7-60 carbon atoms. Incorporation of these compounds unexpectedly provides novel properties to the formulation.
Many underarm compositions are known in the art and described in the cosmetic literature. Such compositions often contain polyorganosiloxanes because of the desirable characteristics they impart. These characteristics include, for example, volatility without cooling, lubricity, and non-tacky delivery of the active agents. The siloxanes incorporated into these compositions, however, are generally limited to those with short alkyl groups such as dimethylpolysiloxanes.
The incorporation of other volatile siloxanes into antiperspirant formulations is also known in the art. For instance Bolich in U.S. Pat. No. 5,002,762 describes antiperspirant compositions incorporating siloxanes of the structure: EQU R.sub.3 SiO[R.sub.2 SiO].sub.x SiR.sub.3
wherein x=1 to 4, the total carbons .ltoreq.14, R is independently C1-C10 alkyl or trialkyl siloxy, and at least one R per molecule must be selected from aryl, alkylaryl, aryl alkyl, C1-C7 hydroxyalkyl, or R1-R2 wherein R1=C1-C9 alkylene and R2 is selected from a wide variety of substituents such as esters, amides, acids, cyanos, etc. Since these materials have a limited number of carbon atoms and contain the above R groups, they do not encompass the materials claimed in the present invention.
Various utilities for alkylmethylsiloxane polymers and copolymers are also known in the art. For instance, Th. Goldschmidt AG product literature on "ABIL.RTM. Silicones" reports that certain polysiloxane polyalkylene copolymers known as ABIL.RTM.-WAX 9800 and ABIL.RTM.-WAX 9801 have utility in skin care applications such as day creams, all purpose creams and body lotions. This literature, however, does not suggest the use of these agents in underarm formulations.
Similarly. U.S. Pat. No. 4,574,082 issued Mar. 4, 1986 describes cosmetics containing a dimethylpolysiloxane in admixture with an organopolysiloxane such as polymethyloctylsiloxane and polymethyloctadecylsiloxane. It is described therein that such mixtures inhibit the phase separation which occurs when waxes are mixed with dimethylsiloxanes. Again, however, this reference does not describe the use of these agents in underarm formulations.
What was not described in the prior art, therefore, is the incorporation of the presently claimed alkylmethylsiloxanes into underarm formulations. The present inventors have now discovered that underarm formulations containing such agents have many desirable characteristics such as modified hardness, reduced whitening, improved feel, compatibilization of ingredients, and controlled vapor pressure.